The Black Box
A black box is one where you can only understand it by looking at the inputs and the outputs.
Proceeding from this, what if the inputs and the outputs themselves are also black boxes? Thus by cause and effect, you have to unravel these inputs and outputs further.
As a result of this unravelling, in order for any progress to be made, you must put an end at one end of this string of black boxes. Either you have an assumed correct output as your axiom, or you start at the beginning as your axiom- axiom meaning an assumed true statement.
Thus either way, you must be able to prove... or to muddy the waters... understand inductively. So with your axiom at n=1, and assuming n=k, proving it's true for n=k+1... or the other way around if you set the axiom at the end.
While this is satisfying, it renders any black box to be understood using axioms... Which you then have dissatisfying problems from this. Statements that are true or false, but not provably so, following Gödel's incompleteness theorem.
And for any sequence of black boxes which you can't easily... or comfortable reduce to axioms... you have no basis for. This I find to be the case of "Cogito Ergo Sum", or "I think therefore I am"- as you have no basis for "Think" and no basis for "Am". Going a step further, you can keep pulling on what it means to think, or what it is to "Am". Is thought still thought if you were predetermined to that thought without any free will about it? Is am, synonymous or identical to ego- in which case you run at odds with those who disagree with ego.
Alas, the Universe is our black box and coffin, and my thought, and being are black boxes themselves. The only understanding we have being probabilistic knowledge of what black boxes produce...